Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Income Statement [Abstract]
Interest income	$ 285,206	$ 278,172	$ 851,626	$ 834,255
Interest expense	(173,654)	(173,040)	(522,027)	(527,438)
Net interest income	111,552	105,132	329,599	306,817
Benefit (provision) for credit losses	12,749	(33,023)	12,146	(34,987)
Net interest income after benefit (provision) for credit losses	124,301	72,109	341,745	271,830
Non-interest income:
Fee and other income	4,270	3,819	13,042	13,667
Derivative gains	169,280	330,196	43,203	471,759
Investment securities gains (losses)	(11,621)	(2,807)	(18,190)	491
Total non-interest income	161,929	331,208	38,055	485,917
Non-interest expense:
Salaries and employee benefits	(13,181)	(14,259)	(38,871)	(41,403)
Other general and administrative expenses	(9,898)	(9,303)	(31,513)	(28,958)
Losses on early extinguishment of debt	(578)	0	(696)	(1,455)
Other non-interest expense	(265)	(301)	(834)	(956)
Total non-interest expense	(23,922)	(23,863)	(71,914)	(72,772)
Income before income taxes	262,308	379,454	307,886	684,975
Income tax provision	(343)	(507)	(524)	(920)
Net income	261,965	378,947	307,362	684,055
Less: Net income attributable to noncontrolling interests	(888)	(1,213)	(1,081)	(1,889)
Net income attributable to CFC	$ 261,077	$ 377,734	$ 306,281	$ 682,166